Question

Use an inequality and the five-step process to solve the problem.

Company A rents copiers for a monthly charge of $360 plus 12 cents per copy. Company B rents copiers for a monthly charge of $720 plus 6 cents per copy. What is the number of copies above which Company A’s charges are the higher of the two?

Answer 1

Answer: at least $6

Explanation:

Let x represent the number of copies , then

Company A;s total will be

A = 360 + 12x

Company B's total will be

B = 720 + 6x

Since it is said that company A's charges are higher , this means that

360 + 12x > 720 + 6x

Solving the resulting linear inequality

Subtract 6x from both sides , the equation becomes

360 + 12x - 6x > 720

360 + 6x > 720

subtract 360 from both sides , we have

6x > 720 - 360

6x > 360

Divide through by 6

x > 360/6

x >60

Since x > 60 , this means that x can be 61 , 62 , 63 .....

Let us use 61 to find the difference between company A's cost and Company B's cost.

A = 360 + 12X

A = 360 + 12(61)

A = 360 + 732

A = 1,092

Therefore , Company A's cost is at least $ 1,092

B = 720 + 6x

B = 720 + 6 ( 61 )

B = 720 + 366

B = 1,086

Therefore , Company B's charges is at least $ 1,086

Difference in charges will be

$1,092 - $ 1,086

Therefore the difference in charges is at least $6